Even with having existed for millions of years, the process for humans to reach 1 billion in population was long and arduous. It is only about 12,000 years ago that humans started engaging in sedentary agriculture. This allowed humans to settle and consistently produce food, rather than hunt and gather throughout.

However, it is with the Industrial Revolution that the means for exponential human population increases was created. New technology, boosts in productivity, and the use of energy allowed for a new frontier in increasing health, sanitation, and standard of living. It is also around this time – in 1804 to be exact – that the earth’s population hit 1 billion people.

Fast forward two hundred years, and the impact of the Industrial Revolution is loud and clear. Now with over 7 billion people, global population has risen so fast that by one estimate, 14% of all human beings that have ever existed are alive today.

Based on a recent UN study, by 2100, our global population is predicted to be between 9.6 and 12.3 billion people. The world will be much different than we know it today in the future.

For starters, the vast majority of growth will happen in the less developed regions of the world. As an example, Nigeria’s population will increase five-fold, from around 174 million today to almost a billion people. It will likely be the 3rd most populous country behind India and China in 2100. Sub-Saharan Africa as a whole could hold up to almost half of the world’s population in the future.

While population has exploded exponentially, unfortunately the resources on our planet are finite. The ecological term for this is “carrying capacity”, which is the maximum population that an environment and resources can sustain indefinitely.

Human carrying capacity is very complex and takes into account many factors, including nutrients, fresh water, environmental conditions, space, technology, medical care, and sanitation. The carrying capacity for humans is not static, and can be changed by adding or subtracting resources from the ecosystem.

While technology has saved the human race time after time, we have not yet found ways to address many of the problems tied to overpopulation such as consumption, changes to climate, inequality, and scarcity of resources.

There are certain realities we will have to face. Here are just some of the issues:
• By 2025, 1.8 billion people will be living in countries or regions with absolute water scarcity.
• The United States uses 1 million gallons of oil every 2 minutes.
• The marginal cost of producing oil and metals has never been higher.
• Food prices are skyrocketing, and availability of essential nutrients (like phosphorus) needed to grow food is becoming scarcer.
• Governments continue to create new currency and debt at unprecedented and unsustainable levels.
• Potential collapses in biodiversity and changes in our climate.